Daily Liveweight Gain statistic for weights

[Skipper-is]

Two main changes here:
First - Rectified missing translates to the weight module

Second - Added two new functions - farm_livestock_weight_dlwg() and farm_livestock_weight_all()

farm_livestock_weight_all() - Returns an array of all weights previously recorded for the asset, with the value, units, label and timestamp.

farm_livestock_weight_dlwg() - Returns the latest daily liveweight gain for assets with more than 2 weights recorded. DLWG (Daily Live Weight Gain) is calculated from the two most recent logs:
DLWG = Weight difference / Time difference
The function returns an array of: timestamp of most recent record, timestamp of the previous record, value of DLWG, and the units.

The function will return an empty array if there is only 1 (or 0) weight recorded for the asset, and will return empty if the units are different.

The Daily Liveweight Gain function is called on the asset page - and shown below the most recent weight for the asset, and is also shown in the "Weight" tab.

[paul121]

@Skipper-is just looked this over, I think this would a great addition! I created a branch with your commit and made a few follow up commits here: 7.x-1.x...paul121:dlwg @mstenta this should be nearly ready to merge.

Changes:

• Return the actual log object with farm_livestock_weight_all and farm_livestock_weight_dlwg (will make the helper functions more useful in the future)
• Change the text from "Daily Liveweight Gain since Date: ## units/day" to read "Daily Liveweight Gain: ## units/day (observed between Date and Date)" where the dates are links to the weight logs.
  • @Skipper-is what do you think about this? "since" makes it seem like the animal is currently growing at this rate which isn't necessarily true. Giving the "observed between" date range is more explicit.
• Generate and return markup for the DLWG text inside farm_livestock_weight_dlwg function. Generating markup could also be implemented in a second function but because the current implementations just want markup in the end this seems fine for now.

[Skipper-is]

I agree that the between date and date is much clearer than since.
Looks good

[mstenta]

Hi @Skipper-is and @paul121 - finally getting around to looking at this. :-)

This is looking good! I was going to try to include this in the 7.x-1.5 release, but there are a few things I want to think more on (mostly minor), and really pushing to get 7.x-1.5 out before I take a week off. So I think I'll pick this back up when I'm back and we can get it ready for inclusion in 7.x-1.6. Thanks for your patience @Skipper-is and both of your work on it!

I have rebased the current work on top of the latest 7.x-1.x commit, pushed to my fork, and added a few changes myself: 7.x-1.x...mstenta:dlwg

My changes are mostly small improvements to the translation strings (separating markup and whitespace out of them, so it is only the text itself, with the exception of the one string that contains links, see https://drupal.stackexchange.com/questions/96622/how-to-use-t-function-for-a-text-with-anchor-links), as well as a few small coding standards/conventions/whitespace tweaks.

One other thing we might consider is merging the farm_livestock_weight_all() function into farm_livestock_weight() and simply adding a $single = TRUE default argument to the function. They are mostly the same, otherwise. If I have a chance to try that out I will.

[mstenta]

I went ahead and merged this. Thanks again @Skipper-is and @paul121 - for the code and the patience! :-)

One other thing we might consider is merging the farm_livestock_weight_all() function into farm_livestock_weight() and simply adding a $single = TRUE default argument to the function. They are mostly the same, otherwise. If I have a chance to try that out I will.

In looking at this again... I decided to leave them as separate functions. If we want to merge them in the future we can always do so and simply deprecate farm_livestock_weight_all().